text: import XRAnchor from './XRAnchor.js'
  
  /*
  XRPlaneAnchor represents a flat surfaces like floors, table tops, or walls.
  */
  export default class XRPlaneAnchor extends XRAnchor {
  	constructor(coordinateSystem, uid=null, center, extent, alignment, geometry) {
  		super(coordinateSystem, uid)
  		this.center = center
  		this.extent = extent
  		this.alignment = alignment
  		this.geometry = geometry
  	}
  
  	get width(){
  		//readonly attribute double width;
  		throw 'Not implemented'
  	}
  
  	get length(){
  		//readonly attribute double length;
  		throw 'Not implemented'
  	}
  }